The present invention relates to telescopes, more specifically to an improved version of reflective telescope whereby the image is corrected intrinsic to the telescope optics. This feature combined with a nearly stationary eyepiece and zoom capability make it particularly useful for terrestrial as well as celestial use.
This invention uses a specially designed telescope mount of my co-pending application. This mount has multiple degrees of freedom to accommodate the additional range of motion requirements and can easily be used in either a horizontal or vertical manner depending on individual comfort preferences and telescope size.
One object of the invention is to improve the optical performance of a reflecting telescope over that of the Newtonian, Cassegrain, Gregorian, Maksutov and Schmidt-Cassegrain types. This optical advantage results from blocking less of the incoming light then these other telescope types. These other telescopes in general block more light as telescope aperture increases, whereas the amount of light blocked by a telescope of the present invention remains constant, independent of telescope size. Furthermore, the blockage of light that does occur is far less then that of even the smallest of the other telescope types.
Another object of the invention is to enhance the usefulness of a reflecting telescope design by incorporating image correcting optics into the design. This allows the telescope to be used for terrestrial as well as celestial observation at a reduced cost. The advantage of this is most apparent when compared to the Newtonian type of telescope which generally cannot be used for terrestrial observation even with external correctors. This is because the image it creates is rotated at some angle dependent on the eyepiece location in addition to being inverted. The other types of reflecting telescopes can have their images corrected, but they require additional external optical components to do it.
Another object of the invention is to enhance the usefulness of a reflecting telescope design by maintaining the eyepiece at a comfortable viewing level. The advantage of this is readily apparent when compared to a large Newtonian telescope of equal size since the Newtonian eyepiece height is directly related to its aperture size. An observer using a large Newtonian design would require a ladder to reach the eyepiece while an observer using the present invention could sit in a chair while observing the same images. Similarly, the advantage is apparent when compared to most other types of telescopes which typically require viewing angle attachments to view objects overhead whereas the present invention does not.
Another object of the invention is to enhance the usefulness of a reflecting telescope by incorporating a zoom feature into the design. This zoom feature utilizes the same optical components as the image corrector thus combining features without increasing cost. Therefore fewer external optical components are required to achieve equal magnification performance. Additionally this feature can eliminate the need for an external finder scope since a reduction in magnification can also be achieved.
Another object of the invention is to achieve a lower cost compared to most other telescope designs. This advantage can be achieved by first using elementary optics rather than custom components, or components requiring specially shaped optical pairs to eliminate aberrations. And second, by reducing the precision requirements of its secondary mirror compared to the other telescopes mentioned. And third, by eliminating the need for as many external optical components as possible; This includes components such as finder scopes, viewing angle attachments, zoom attachments, image correctors, image reducers, and multiple eyepieces all of which the other telescope types use at substantial additional cost.
Another object of the invention is to create a reflecting telescope design that is rugged enough to remain collimated after being set at a factory. The advantage of this is most apparent when compared to the Newtonian design which generally requires collimation with each use, particularly when transported, to maintain optimum performance. The very stable design structure of the present invention makes it useful as a spotting type field telescope which generally cannot be done effectively using a reflective type telescope.
These and other objects and advantages of the present invention will become increasingly apparent upon consideration of the drawings and ensuing description.